In the related art, when welding of a structure (a material to be welded) that uses a metal, a nonferrous metal, or the like as a base material, non-consumable electrode type gas shielded arc welding referred to as GTAW (Gas Tungsten Arc welding) such as TIG welding (Tungsten Inert Gas welding) or plasma arc welding, consumable electrode type gas shielded arc welding (also referred to as semi-automatic arc welding) referred to as GMAW (Gas Metal Arc welding) such as MIG welding (Metal Inert Gas welding), MAG welding (Metal Active Gas welding), or CO2 gas shielded arc welding have been used.
In these welding methods, in general, a welding torch having a single nozzle structure is used, an arc is generated between an electrode and a material to be melted, and welding is performed. Moreover, an inert gas (shielding gas) such as argon or helium is discharged from a nozzle that surrounds the periphery of the electrode during welding, and welding is performed while being shielded from the atmosphere (air) using the shielding gas.
In addition, in TIG welding, in order to make a deep weld penetration in the welded portion, mixed gas in which hydrogen is added to argon or mixed gas in which helium is added to argon is used as the shielding gas. In addition, for example, in TIG welding of an austenitic stainless steel, a welding torch having a double nozzle structure is used in which an inert gas flows to the inside and oxidized gas flows to the outside, and thereby, welding is performed so that the weld penetration depth is deeper (refer to Patent Document 1).
On the other hand, also in MIG welding, a welding torch having a double nozzle structure is used in which a primary shielding gas flows to the inside and a secondary shielding gas flows to the outside (refer to Patent Document 2).
Here, a TIG welding torch 100A of the related art having a single nozzle structure shown in FIGS. 11A and 11B will be described. Moreover, FIG. 11A is a main portion cross-sectional view of the TIG welding torch 100A having a single nozzle structure and FIG. 11B is an assembly diagram of the TIG welding torch 100A having a single nozzle structure.
As shown in FIGS. 11A and 11B, the TIG welding torch 100A generally includes a non-consumable electrode 101 that generates an arc between the electrode and a material to be welded, a collet 102 that supports the non-consumable electrode 101 in a state where the electrode is inserted into the collet, a collet body 103A that holds the collet 102 inside the collet body in a state where the non-consumable electrode 101 protrudes from the tip side of the collet body, a torch body 104 to which the collet body 103A is mounted, a torch nozzle 105A that is mounted to the collet body 103A surrounding the periphery of the non-consumable electrode 101 and discharges shielding gas, a front gasket 106 that is disposed between the torch body 104 and the torch nozzle 105A, a torch cap 108 that is mounted in a state where a rear gasket 107 is disposed between the torch body 104 and the torch cap, and a handle 109 that is mounted to the torch body 104.
In addition, in the TIG welding torch 100A, after a welding cable C is connected, an arc is generated between the non-consumable electrode 101 and the material to be welded while the shielding gas is discharged from the torch nozzle 105A, and welding is performed.
Next, a TIG welding torch 100B of the related art having a single nozzle structure shown in FIGS. 12A and 12B will be described. Moreover, FIG. 12A is a main portion cross-sectional view of the TIG welding torch 100B having a single nozzle structure and FIG. 12B is an assembly diagram of the TIG welding torch 100B having a single nozzle structure.
As shown in FIGS. 12A and 12B, the TIG welding torch 100B includes a gas lens type collet body 103B instead of the collet body 103A. The collet body 103B is configured so as to be integrally formed with a gas lens 110 that corrects the flow of the shielding gas discharged from a torch nozzle 105B. In addition, in accordance with the increase in the diameter of the collet body 103B, the diameter of the torch nozzle 105B is increased to a greater extent than that of the torch nozzle 105A. Apart from that, the TIG welding torch 100B generally has the same configuration as that of the TIG welding torch 100A. Therefore, apart from this difference, descriptions of the same portions as the TIG welding torch 100A are omitted and the same reference numerals are given to the same portions in the drawings.
In the TIG welding torch 100B, after the welding cable C is connected, an arc is generated between the non-consumable electrode 101 and the material to be welded while the flow of the shielding gas corrected by the gas lens 110 is discharged from the torch nozzle 105B, and welding is performed. In the gas lens type TIG welding torch 100B, the flow of the shielding gas that is discharged from the torch nozzle 105B is corrected by the gas lens 110, and thereby, the shielding effect from the atmosphere (air) due to the shielding gas may be enhanced.
Next, a TIG welding torch 100C of the related art having a double nozzle structure shown in FIG. 13 will be described. Moreover, FIG. 13 is an assembly diagram in which a main portion of the TIG welding torch 100C having the double nozzle structure is shown in a cross-section.
As shown in FIG. 13, instead of the torch nozzle 105A, the TIG welding torch 100C includes an inner nozzle 105a that is mounted to a collet body 103C surrounding the periphery of the non-consumable electrode 101 and discharges a first shielding gas, and an outer nozzle 105b that is mounted to the inner nozzle 105a surrounding the periphery of the inner nozzle 105a and discharges a second shielding gas. Apart from that, the TIG welding torch 100C generally has the same configuration as that of the TIG welding torch 100A. Therefore, apart from this difference, descriptions of the same portions as the TIG welding torch 100A are omitted and the same reference numerals are given to the same portions in the drawings.
In the TIG welding torch 100C, after the welding cable C is connected, an arc is generated between the non-consumable electrode 101 and the material to be welded while the first shielding gas is discharged from the inner nozzle 105a and the second shielding gas is discharged from the outer nozzle 105b, and welding is performed. In the TIG welding torch 100C having the double nozzle structure, there are two types of shielding gas, and thereby, the weld penetration depth can be deeper.
Next, an MIG welding torch 200 of the related art having a single nozzle structure shown in FIG. 14 will be described. Moreover, FIG. 14 is an assembly diagram in which a main portion of the MIG welding torch 200 having the single nozzle structure is shown in a cross-section.
As shown in FIG. 14, the MIG welding torch 200 generally includes a consumable electrode 201 that generates an arc toward a material to be welded, a contact tip 202 that guides and concurrently sends out the consumable electrode 201 from the tip side of the contact tip, a torch body 203 to which the contact tip 202 is mounted, a torch nozzle 204 that is mounted to the torch body 203 surrounding the periphery of the contact tip 202 and discharges shielding gas, and a handle 205 that is mounted to the torch body 203.
In addition, in the MIG welding torch 200, after a welding cable D is connected, an arc is generated between the consumable electrode 201 and the material to be welded while the shielding gas is discharged from the torch nozzle 204, and welding is performed. Moreover, in the MIG welding torch 200, since the consumable electrode 201 itself is welded while being melted by the arc, a structure is configured in which the consumable electrode 201 is automatically fed through the inside of the handle 205.